Electrical plug switch



L. N HAMPTON ELECTRICAL PLUGSWITCH Oct. 27 1925' Filed De.

hue/77w? A 90/7 /V /1a/77 0f0/z by W Patented Oct. 27, 1925. 1,559,250

UNITED STATESPATE'NT OFFICE.

LEON N. HAMPTON, OF NRW YORK, N. Y., ASSIGNO R TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTRICAL PLUG SWITCH. A

Application filed December 21, 1920. Serial No. 432,252.

To all whom it may concern: which they carry, by means of screws fasten- 55 Be it known that I, LnonN. HAMPTON, a ing through the cord tip lugs provided at citizen of the United States, residing at New their ends.

York, in the county of Bronx, State of New The invention will be understood more York, have invented certain new and useful completely by reference to the drawing Improvements in Electrical Plug Switches, which shows its preferred embodiment. 60 of which the following is a full, clear, con- Fig. 1 represents the plug in place contactcis'e, and exact description. ing with the line springs of the distributing This invention relates to electrical switchframe. Fig. 2 is a cross-sectional view ing devices such as are employed in teletaken at the plane 22. Fig. 3 is a perspecphone central oflices for testing separately tive view with sections cut away to show 65 the conditions of a simscribers line within "the internal construction of the hinge joint. and without the exchange system. Referring to the drawings, the construc- In the majority of central offices at prestion of the distributing frameis shown coment in use, a distributing frame is used to posed of the main vertical rib 1 supporting cross connect'the outside portion of each contact springs 2 at the end of whichcarbon 70 subscribers line with terminals correspo-ndprotector blocks 7 are supported against ing to the subscribers drop number. At rib 1; springs 3 to co-operate with the end this frameare located all the devices mo of the heat coil protector; and springs 4 tecting the central oflice from dangerous curalso adapted to normally contact with heat rent potentials and continued excessive curcoils. The springs 2, 3 and 4 are bolted to 7 rents. The protection usually employed the rib 1 by means of bolts and insulated against the latter consists of a pair of heat from each other by means of strips of incoils inserted between contact springs sulating material. 6. At the end of the suitably formed for the convenient insersprings 4, a slot 8 is out which cooperates tion of the coils by the attendant test man. with a projection at one end of the heat Distributing frames and heat coils, being c0il't0 hold it in place.

well known in the art, need no further de- The test plug is composed of two fiat scription here. Plugs of the class to which metallic arms 9 having free ends 10 that conthis invention relates are adapted to be inform to the configuration of the ends of the serted in place of such heat coils between springs 4; a pair of contact blocks 11 prefso the inside and outside line spring contacts erably of metal supported on the arms 9 by and are connected by means of suitable con means of screws 12 and insulated from the ductors to the testing desk. arms by strips of insulating material 13 and 35 The object of the invention is to provide insulating collars 14 for the shanks of the a -plug of the character described which is screws 12; two stirrup supporting members of simple construction and is capable of easy 15 and 16 insulatingly supporting the arm's manipulation on the part of the user. 9 by means of screws 17 and the strip of To this end the plug is providedwith a insulating material 18; and a hinged joint 40 pair ofarms, one for each side of the line, 19 cooperating with the members 15 and 16 each arm comprising a flat metal strip bent to allow relative rotary motionin the arms 9. at one end to conform to the shape of the The hinge joint 19 has two concentric spring with which it contacts and a conducrings, an inner ring 20 and an outer ring 21. tive block insulatingly supported by each The inner ring is provided with a groove 22 45 arm and provided with a contacting surface on its circumference into which is .inserted also shaped to conform with the contour of a spiral'spring 23 one end 2-t of which is the spring with which it contacts. The two bent so as to engage wfith the ring 20 in the arms are supported on separate frame memnotch 25 and the other end of which 26 is bers to cooperate through a hinge joint havadapted to engage with the outer ring 21 at 50 ing aspiral spring which keeps the two arms the notch 27 The end 24 projects beyond resiliently held apart. The tendency in the the outer edge of the ring 20 and to allow arms to spread assists greatl in handling a space for it to move freely, a portion of the plug. Suitable cord'con uctors are atthe outer ring 21 is cut away leaving apertached to the arms and the contact blocks ture 38. The stirrup 15 is attached to the outer ring 21 by means of screws 28 and the stirrup 16 is attached to the inner ring 20 by means of the screws '29.

Each of the contact blocks 11 is provided with a stepped surface 30 so that a large area contact is made therewith by the springs 2 and 3. The knee in this stepped surface 30 also prevents the block from being easily displaced. At the break in the surface 30 are two flanges 39 which fit on either side of the contact spring to laterally support the block in. contact with the spring and to prevent .turning of the plug in place. On each of the arms 9 are located a pair of pegs ,31 which cooperate with the groove 8 of springs 4' to prevent the plug from twisting out of position between the distributing frame springs.

The conductors 32 and 33 of the cord 34 are introduced into the plug through the space left between outer ring 21 and the bottom of the stirrups 15 and 16. These conductors are attached to the contact-arm 9 and contact blocks 11 in any suitable fashion, the preferred manner of fastening them being by means of screws 35 threaded directly into the contact member. The tie cord 36 of the cord 34 is attached to a loop projection 37 integrally formed on the ring 21.

By virtue of the tension in the spring 23, the arms 9 tend to spread apart so that someslight pressure is necessary to be exerted on these arms to bring them together sufficiently for insertion between distributing frame springs. This materially assists the user in performing this operation since one of his hands would naturally be hold-.

ing-his pliers and the heat coils which have been removed from the frame. With the assistance of this tendency in the arms of the plug to spread, he can insert the plug with the use of only one hand.

What is claimed is:

1. In an electrical test plug, a pair of contact arms, each having a flat length and bentat one end to conform to the configuration of a distributing frame spring; and

length of each said arm,

vided with a a contact member insulatingly supported on the inner side of a portion of the flat and provided with a stepped contacting surface.

In an electrical test plug, a pair of contact arms, each having a flat length bent at one end to conform to the configuration of adistributing frame spring; a contact member for each of said arms, each of said contact .members being insulatingly mounted on the inner side of a portion of the flat length of the arm and provided with a stepped contacting surface; and a hinged oint cooperating with said arms to permit relative movement between said arms.

3. In an electrical test plug, a pair of contact arms, each having an end portion bent to conform to the configuration of a corresponding distributing frame spring contact; a contact member insulatingly supported on each of said arms and provided with a surface conforming with a configuration of a corresponding distributing frame spring; a stirrup member insulatingly supporting each of said arms; and a hinged joint comprising a pair of concentric ring members, each of said rings supporting one of said stirrup members, and a spiral spring interacting between the saidring members tending to keep the contact arms apart.

eL'In an electrical test plug, a pair of contact arms, a contact member insulatingly supported on each said arm, and prostepped inner surface, and a flange provided on each side of said contact member.

5. In an electrical test plug, a pair of contact arms, contact members insulatingly supported on said arms, a hinged joint for the arms, means upon the joint to partially limit the spreading or the closing of the arms, and aspring member tending to spread the arms.

' In witness whereof, I hereunto subscribe myname thisl7th day of December A. D.,

LEON N. HAMPTON. 

